xref: /dragonfly/lib/libc/xdr/xdr_reference.c (revision 0bb9290e)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user.
8  *
9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12  *
13  * Sun RPC is provided with no support and without any obligation on the
14  * part of Sun Microsystems, Inc. to assist in its use, correction,
15  * modification or enhancement.
16  *
17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19  * OR ANY PART THEREOF.
20  *
21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22  * or profits or other special, indirect and consequential damages, even if
23  * Sun has been advised of the possibility of such damages.
24  *
25  * Sun Microsystems, Inc.
26  * 2550 Garcia Avenue
27  * Mountain View, California  94043
28  *
29  * @(#)xdr_reference.c 1.11 87/08/11 SMI
30  * @(#)xdr_reference.c	2.1 88/07/29 4.0 RPCSRC
31  * $FreeBSD: src/lib/libc/xdr/xdr_reference.c,v 1.8 1999/08/28 00:02:56 peter Exp $
32  * $DragonFly: src/lib/libc/xdr/xdr_reference.c,v 1.4 2005/12/05 00:47:57 swildner Exp $
33  */
34 
35 /*
36  * xdr_reference.c, Generic XDR routines impelmentation.
37  *
38  * Copyright (C) 1987, Sun Microsystems, Inc.
39  *
40  * These are the "non-trivial" xdr primitives used to serialize and de-serialize
41  * "pointers".  See xdr.h for more info on the interface to xdr.
42  */
43 
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <rpc/types.h>
48 #include <rpc/xdr.h>
49 
50 #define LASTUNSIGNED ((u_int) 0-1)
51 
52 /*
53  * XDR an indirect pointer
54  * xdr_reference is for recursively translating a structure that is
55  * referenced by a pointer inside the structure that is currently being
56  * translated.  pp references a pointer to storage. If *pp is null
57  * the  necessary storage is allocated.
58  * size is the sizeof the referneced structure.
59  * proc is the routine to handle the referenced structure.
60  *
61  * Parameters:
62  *     pp:	the pointer to work on
63  *     size:	size of the object pointed to
64  *     proc:	xdr routine to handle the object
65  */
66 bool_t
67 xdr_reference(XDR *xdrs, caddr_t *pp, u_int size, xdrproc_t proc)
68 {
69 	caddr_t loc = *pp;
70 	bool_t stat;
71 
72 	if (loc == NULL)
73 		switch (xdrs->x_op) {
74 		case XDR_FREE:
75 			return (TRUE);
76 
77 		case XDR_DECODE:
78 			*pp = loc = (caddr_t) mem_alloc(size);
79 			if (loc == NULL) {
80 				fprintf(stderr,
81 				    "xdr_reference: out of memory\n");
82 				return (FALSE);
83 			}
84 			memset(loc, 0, (int)size);
85 			break;
86 		case XDR_ENCODE:
87 			break;
88 	}
89 
90 	stat = (*proc)(xdrs, loc, LASTUNSIGNED);
91 
92 	if (xdrs->x_op == XDR_FREE) {
93 		mem_free(loc, size);
94 		*pp = NULL;
95 	}
96 	return (stat);
97 }
98 
99 
100 /*
101  * xdr_pointer():
102  *
103  * XDR a pointer to a possibly recursive data structure. This
104  * differs with xdr_reference in that it can serialize/deserialiaze
105  * trees correctly.
106  *
107  *  What's sent is actually a union:
108  *
109  *  union object_pointer switch (boolean b) {
110  *  case TRUE: object_data data;
111  *  case FALSE: void nothing;
112  *  }
113  *
114  * > objpp: Pointer to the pointer to the object.
115  * > obj_size: size of the object.
116  * > xdr_obj: routine to XDR an object.
117  *
118  */
119 bool_t
120 xdr_pointer(XDR *xdrs, char **objpp, u_int obj_size, xdrproc_t xdr_obj)
121 {
122 	bool_t more_data;
123 
124 	more_data = (*objpp != NULL);
125 	if (! xdr_bool(xdrs,&more_data)) {
126 		return (FALSE);
127 	}
128 	if (! more_data) {
129 		*objpp = NULL;
130 		return (TRUE);
131 	}
132 	return (xdr_reference(xdrs,objpp,obj_size,xdr_obj));
133 }
134